Let us note another characteristic feature in the Machians’ incredible perversion of materialism. Valentinov endeavours to beat the Marxists by comparing them to Büchner, who supposedly has much in common with Plekhanov, although Engels sharply dissociated himself from Buchner. Bogdanov, approaching the same question from another angle, defends, as it were, the “materialism of the natural scientists,” which, he says, “is usually spoken of with a certain contempt” (Empirio-Monism, Bk. III, p. x). Both Valentinov and Bogdanov are wretchedly muddled on this question. Marx and Engels always “spoke contemptuously” of bad socialists; but from this it follows that they demanded the teaching of correct socialism, scientific socialism, and not a flight from socialism to bourgeois views. Marx and Engels always condemned bad (and, particularly, anti-dialectical) materialism; but they condemned it from the standpoint of a higher, more advanced dialectical materialism, and not from the standpoint of Humism or Berkeleianism. Marx, Engels and Dietzgen would discuss the bad materialists, reason with them and seek to correct their errors. But they would not even discuss the Humeans and Berkeleians, Mach and Avenarius, confining themselves to a single still more contemptuous remark about their trend as a whole. Therefore, the endless faces and grimaces made by our Machians over Holbach and Co., Büchner and Co., etc., are absolutely nothing but an attempt to throw dust in the eyes of the public, a cover for the departure of Machism as a whole from the very foundations of materialism in general, and a fear to take up a straightforward and clear position with regard to Engels.
And it would be hard to express oneself more clearly on the French materialism of the eighteenth century and on Büchner, Vogt and Moleschott, than Engels does at the end of Chapter II of his Ludwig Feuerbach. It is impossible not to understand Engels, unless one deliberately wishes to distort him. Marx and I are materialists—says Engels in this chapter, explaining what fundamentally distinguishes all schools of materialism from the whole camp of the idealists, from all the Kantians and Humeans in general. And Engels reproaches Feuerbach for a certain pusillanimity, a certain frivolity of thought, as expressed in his rejection at times of materialism in general because of the mistakes of one or another school of materialists. Feuerbach “should not have confounded the doctrines of these hedge-preachers [Büchner and Co.] with materialism in general,” says Engels (p. 21). Only minds that are spoilt by reading and credulously accepting the doctrines of the German reactionary professors could have misunderstood the nature of such reproaches levelled by Engels at Feuerbach.
Engels says very clearly that Büchner and Co. “by no means overcame the limitations of their teachers,” i.e.,the materialists of the eighteenth century, that they had not made a single step forward. And it is for this, and this alone, that Engels took Büchner and Co. to task; not for their materialism, as the ignoramuses think, but because they did not advance materialism, because “it was quite outside their scope to develop the theory [of materialism] any further.” It was for this alone that Engels took Büchner and Co. to task. And thereupon point by point Engels enumerates three fundamental “limitations” (Beschränktheit) of the French materialists of the eighteenth century, from which Marx and Engels had emancipated themselves, but from which Büchner and Co. were unable to emancipate themselves. The first limitation was that the views of the old materialists were “mechanical,” in the sense that they believed in “the exclusive application of the standards of mechanics to processes of a chemical and organic nature” (p. 19). We shall see in the next chapter that failure to understand these words of Engels’ caused certain people to succumb to idealism through the new physics. Engels does not reject mechanical materialism for the faults attributed to it by physicists of the “recent” idealist (alias Machian) trend. The second limitation was the metaphysical character of the views of the old materialists, meaning the “anti-dialectical character of their philosophy.” This limitation is fully shared with Büchner and Co. by our Machians, who, as we have seen, entirely failed to understand Engels’ application of dialectics to epistemology (for example, absolute and relative truth). The third limitation was the preservation of idealism “up above,” in the realm of the social sciences, a non-understanding of historical materialism.
Having enumerated these three “limitations” and explained them with exhaustive clarity (pp. 19-21), Engels then and there adds that they (Büchner and Co.) did not emerge “from these limits” (über diese Schranken).
Exclusively for these three things and exclusively within these limits, does Engels refute both the materialism of the eighteenth century and the doctrines of Büchner and Co.! On all other, more elementary, questions of materialism (questions distorted by the Machians) there is and can be no difference between Marx and Engels on the one hand and all these old materialists on the other. It was only the Russian Machians who brought confusion into this perfectly clear question, since for their West-European teachers and co-thinkers the radical difference between the line of Mach and his friends and the line of the materialists generally is perfectly obvious. Our Machians found it necessary to confuse the issue in order to represent their break with Marxism and their desertion to the camp of bourgeois philosophy as “minor corrections” of Marxism!
Take Dühring. It is hard to imagine anything more contemptuous than the opinion of him expressed by Engels. But at the same time that Dühring was criticised by Engels, just see how he was criticised by Leclair, who praises Mach’s “revolutionising philosophy.” Leclair regards Dühring as the “extreme Left” of materialism, which “without any evasion declares sensation, as well as every activity of consciousness and intelligence in general, to be the secretion, function, supreme flower, aggregate effect, etc., of the animal organism” (Der Realismus, etc., 1879, S. 23-24).
Is it for this that Engels criticised Dühring? No. In this he was in full agreement with Dühring, as he was with every other materialist. He criticised Dühring from the diametrically opposite standpoint, namely, for the inconsistency of his materialism, for his idealist fancies, which left a loophole for fideism.
“Nature itself works both within ideating beings and from without, in order to create the required knowledge of the course of things by systematically producing coherent views.” Leclair quotes these words of Dühring’s and savagely attacks the materialism of such a point of view, the “crude metaphysics” of this materialism, the “self-deception,” etc., etc. (pp. 160 and 161-63).
Is it for this that Engels criticised Dühring? No. He ridiculed all florid language, but as regards the cognition of objective law in nature, reflected by the consciousness, Engels was fully in agreement with Dühring, as he was with every other materialist.
“Thought is a form of reality higher than the rest. . . . A fundamental premise is the independence and distinction of the materially real world from the groups of manifestations of the consciousness.” Leclair quotes these words of Dühring’s together with a number of Dühring’s attacks on Kant, etc., and for this accuses Dühring of “metaphysics” (pp. 218-22), of subscribing to “a metaphysical dogma,” etc.
Is it for this that Engels criticised Dühring? No. That the world exists independently of the mind and that every deviation from this truth on the part of the Kantians, Humeans, Berkeleians, and so forth, is false, on this point Engels was fully in agreement with Dühring, as he was with every other materialist. Had Engels seen from what angle Leclair, in the spirit of Mach, criticised Dühring, he would have called both these philosophical reactionaries names a hundred times more contemptuous than those he called Dühring. To Leclair Dühring was the incarnation of pernicious realism and materialism (cf. also Beiträge zu einer monistischen Erkenntnistheorie, 1882, S. 45). In 1878, W. Schuppe, teacher and comrade-in-arms of Mach, accused Dühring of “visionary realism” (Traumrealismus) in revenge for the epithet “visionary idealism” which Dühring had hurled against all idealists. For Engels, on the contrary, Dühring was not a sufficiently steadfast, clear and consistent materialist.
Marx and Engels, as well as J. Dietzgen, entered the philosophical arena at a time when materialism reigned among the advanced intellectuals in general, and in working-class circles in particular. It is therefore quite natural that they should have devoted their attention not to a repetition of old ideas but to a serious theoretical development of materialism, its application to history, in other words, to the completion of the edifice of materialist philosophy up to its summit. It is quite natural that in the sphere of epistemology they confined themselves to correcting Feuerbach’s errors, to ridiculing the banalities of the materialist Dühring, to criticising the errors of Büchner (see J. Dietzgen), to emphasising what these most widely known and popular writers among the workers particularly lacked, namely, dialectics. Marx, Engels and J. Dietzgen did not worry about the elementary truths of materialism, which had been cried by the hucksters in dozens of books, but devoted all their attention to ensuring that these elementary truths should not be vulgarised, should not be over-simplified, should not lead to stagnation of thought (“materialism below, idealism above”), to forgetfulness of the valuable fruit of the idealist systems, Hegelian dialectics—that pearl which those farmyard cocks, the Büchners, the Dührings and Co. (as well as Leclair, Mach, Avenarius and so forth), could not pick out from the dungheap of absolute idealism.
If one envisages at all concretely the historical conditions in which the philosophical works of Engels and J. Dietzgen were written, it will be perfectly clear why they were more concerned to dissociate themselves from the vulgarisation of the elementary truths of materialism than to defend the truths themselves. Marx and Engels were similarly more concerned to dissociate themselves from the vulgarisation of the fundamental demands of political democracy than to defend these demands.
Only disciples of the philosophical reactionaries could have “failed to notice” this circumstance, and could have presented the case to their readers in such a way as to make it appear that Marx and Engels did not know what being a materialist means.
 Dr. Wilhelm Schuppe, Erkenntnistheoretische Logik [Epistemological Logic], Bonn, 1878, S. 56. —Lenin
 See K. Marx and F. Engels, Selected Works, Vol. II, Moscow, 1958, p. 375.